Battery pack to relieve internal pressure during thermal runaway

Abstract

A battery pack for removing internal pressure during thermal runaway according to one embodiment of the present invention includes one or more battery modules; and a case for accommodating the battery modules, the case including a vent hole for discharging gas from inside; and a vent tape attached to the case to cover the vent hole.

Description

[Technical field]

[0001] The present invention relates to a battery pack, and more particularly to a battery pack capable of effectively removing internal pressure during thermal runaway. [Background technology]

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged, and are used not only in portable devices but also in electric vehicles (EVs) and hybrid vehicles (HEVs) that are powered by electric sources.

[0003] Currently, the types of secondary batteries that are widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such unit battery cells is about 2.5V to 4.6V. Therefore, when a higher output voltage is required, a battery pack is configured by connecting a number of battery cells in series. Also, a battery pack may be configured by connecting a number of battery cells in parallel depending on the charge / discharge capacity required for the battery pack. Therefore, the number of battery cells included in the battery pack may be set variously depending on the required output voltage or charge / discharge capacity.

[0004] When a battery pack is constructed by connecting a number of battery cells in series and parallel, a common method is to construct a battery module consisting of at least one battery cell, preferably a number of battery cells, and then use at least one of such battery modules to construct a battery pack by adding other components. Here, the battery module refers to a component in which a number of battery cells are connected in series or parallel, and the battery pack refers to a component in which a number of battery modules are connected in series or parallel to increase capacity and output.

[0005] Generally, in a vehicle battery pack, a plurality of battery modules or battery module assemblies are arranged on the same plane in order to maintain structural stability.

[0006] In addition, if such a battery pack is overcharged, high energy flows instantaneously, and the positive electrode material becomes chemically activated due to overcharging or short circuit, which can react rapidly with the electrolyte to generate a large amount of gas. As a result, the internal pressure and temperature of the battery pack rises rapidly, which can lead to the battery pack exploding.

[0007] Conventionally, as shown in FIG. 1, when a battery pack 10 experiences thermal runaway, gas leaks through a rubber seal gasket provided between an upper housing 1 and a lower housing 2. In such a case, the gas cannot be quickly discharged, and deformation of the external housing and damage to the seal may occur, which may result in the outbreak of a flame outside the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a battery pack capable of quickly removing internal pressure in the event of thermal runaway. [Means for solving the problem]

[0009] A battery pack for removing internal pressure during thermal runaway according to one embodiment of the present invention includes one or more battery modules; and a case for accommodating the battery modules, the case including a vent hole for discharging gas from inside; and a vent tape attached to the case to cover the vent hole.

[0010] The case further includes a lower housing and an upper housing coupled to an upper side of the lower housing.

[0011] Also, preferably, the vent hole is disposed in the upper housing.

[0012] Moreover, a plurality of the vent holes are provided.

[0013] The vent tape also includes a tear line.

[0014] Additionally, the cut line is positioned outside the vent hole.

[0015] The cut line is formed so as to surround the vent hole.

[0016] The cut line may be circular.

[0017] The cut line may be in the shape of a circular arc.

[0018] According to another embodiment of the present invention, a battery pack for removing internal pressure during thermal runaway includes one or more battery modules; and a case for accommodating the battery modules, the case including a vent hole for discharging gas from the inside; a gas exhaust tube communicating with the vent hole and extending from the case to the outside; and a vent tape covering an end of the gas exhaust tube.

[0019] The gas exhaust tube further includes an extension disposed at an end of the gas exhaust tube and extending outwardly from the end of the gas exhaust tube.

[0020] The vent tape is attached to the extension portion.

[0021] The vent tape may also include a tear line, the tear line being disposed outside the inner circumferential surface of the gas exhaust tube in the expanded portion.

[0022] The cut line may be provided so as to surround the inner circumference of the gas exhaust tube. Effect of the Invention

[0023] According to the battery pack of the present invention, it is possible to obtain the effect of being able to quickly remove internal pressure in the event of thermal runaway. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 illustrates a conventional battery pack. [Diagram 2] FIG. 1 is a diagram showing a battery pack according to a first embodiment of the present invention. [Diagram 3] FIG. 3 is a detailed view showing part A in FIG. 2. [Figure 4] 3 is a cross-sectional view of one side of the battery pack in FIG. 2. [Diagram 5] FIG. 11 is an enlarged view showing a vent tape in a battery pack for removing internal pressure during thermal runaway according to a second embodiment of the present invention. [Figure 6] FIG. 13 is an enlarged view showing a vent tape in a battery pack for removing internal pressure during thermal runaway according to a third embodiment of the present invention. [Figure 7] FIG. 13 is an enlarged view showing a vent tape in a battery pack for removing internal pressure during thermal runaway according to a third embodiment of the present invention. [Figure 8] FIG. 7 is a diagram showing how the internal gas in FIG. 6 is discharged through a vent hole. [Figure 9] FIG. 8 is a diagram showing how the internal gas in FIG. 7 is discharged through a vent hole. [Figure 10] FIG. 11 is a diagram showing a battery pack according to a fourth embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing a battery pack according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The advantages and features of the present invention, as well as the method of achieving the same, will become apparent from the detailed description of the embodiments with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be realized in various different forms. However, the embodiments are provided for a complete disclosure of the present invention and to fully inform those skilled in the art of the present invention of the scope of the invention, and the present invention should be defined by the scope of the claims. Therefore, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid obscuring the present invention. The same reference numerals refer to the same components throughout the specification.

[0026] In the drawings, the thickness of layers and regions is exaggerated for clarity. Similar parts are labeled with the same reference numerals throughout the specification. When a part, such as a layer, film, region, or plate, is said to be "on" another part, this includes not only when it is "directly on" the other part, but also when there is another part in between. In contrast, when a part is said to be "directly on" the other part, it means that there is no other part in between. When a part, such as a layer, film, region, or plate, is said to be "under" the other part, this includes not only when it is "directly under" the other part, but also when there is another part in between. In contrast, when a part is said to be "directly under" the other part, it means that there is no other part in between.

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a battery pack for removing internal pressure during thermal runaway according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0028] FIG. 2 is a diagram showing a battery pack according to one embodiment of the present invention, FIG. 3 is a detailed diagram showing part A in FIG. 2, and FIG. 4 is a diagram showing a cross-section of one side of the battery pack in FIG.

[0029] A battery pack 1000 for removing internal pressure during thermal runaway according to an embodiment of the present invention includes one or more battery modules 500 and a case 50 for accommodating the battery modules 500 , and the case 50 includes an upper housing 100 and a lower housing 200 .

[0030] The battery module 500 contained in the battery pack 1000 includes a plurality of battery cells (not shown), and each battery cell may be, for example, a pouch-type battery cell. For example, the battery module 500 includes a plurality of battery cells stacked on one another, and each battery cell has an electrode lead at a front end and a rear end, respectively, and a positive electrode lead may be provided at the front end and a negative electrode lead at the rear end. The plurality of battery cells in the battery module 500 may be stacked so as to be electrically connected to each other. The battery cells are not limited to pouch-type battery cells, and may be battery cells having other shapes, such as rectangular battery cells, and multiple battery cells may be housed within the case of the battery module 500.

[0031] The case 50 is for housing a plurality of battery modules 500, and includes an upper housing 100 and a lower housing 200, and further includes a gasket 400 between the upper and lower housings 100 and 200.

[0032] The lower housing 200 can accommodate a plurality of battery modules 500, and the upper housing 100 is coupled to the upper side of the lower housing 200, forming an internal space inside the case 50 in which the battery modules 500 are accommodated.

[0033] The gasket 400 disposed between the upper housing 100 and the lower housing 200 is provided for sealing between the upper housing 100 and the lower housing 200, and is disposed over the entire joint portion of the upper and lower housings 100 and 200, forming a closed loop shape on a plane. The gasket may be made of rubber or other materials.

[0034] In the present invention, a vent hole 110 is formed in the case 50. The vent hole 110 is for discharging gas generated inside the battery pack 1000 during thermal runaway. An example in which the vent hole 110 is formed in the upper housing 100 is shown in FIGS.

[0035] In a battery pack, if overcharging occurs, high energy flows instantaneously, and the positive electrode material becomes chemically activated due to overcharging or short circuit, which can react rapidly with the electrolyte and generate a large amount of gas, causing the internal pressure and temperature of the battery pack to rise suddenly, which can lead to the battery pack exploding.

[0036] In the present invention, gas generated inside the battery pack 1000 during thermal runaway is discharged through the vent hole 110, thereby making it possible to prevent deformation of the outer housing and damage to the seal due to an increase in internal pressure. Although an example in which the vent hole 110 is formed in the upper housing 100 is shown in Figs. 2 and 3, the vent hole 110 may be formed in the lower housing 200.

[0037] Two or more vent holes 110 may be provided in the case 50 as shown in the figure.

[0038] In addition, vent tape 300 is attached to the upper part of vent hole 110. Vent tape 300 is attached to case 50 or upper housing 100 so as to cover vent hole 110. Vent tape 300 has an area larger than vent hole 110, and is attached to case 50 or upper housing 100 by adhesive applied to the back surface thereof.

[0039] Such vent tape 300 normally blocks the inside of the case 50 from the outside, preventing foreign matter from entering. However, in the event of thermal runaway of the battery pack, when a certain pressure is generated due to an increase in the internal pressure of the battery pack 1000, the vent tape 300 loses its adhesive strength, causing the vent tape 300 to separate from the case 50 or upper housing 100, and allowing internal gas to be discharged through the vent hole 110.

[0040] In the past, when a battery pack experienced thermal runaway, gas leaked through the gasket between the upper and lower housings, preventing the gas from being quickly discharged, resulting in deformation of the external housing and damage to the seal. In the present invention, when the internal pressure of the battery pack 1000 increases due to gas generated inside the battery pack 1000 and exceeds a certain pressure, the vent tape 300 is separated from the case 50 or the upper housing 100, and the internal gas is discharged through the vent hole 110, quickly removing the internal pressure. This allows the internal pressure to be removed at the beginning of a thermal explosion, preventing the occurrence of a flame outside the battery pack.

[0041] Next, a battery pack for removing internal pressure during thermal runaway according to a second embodiment of the present invention will be described. Fig. 5 is an enlarged view of a vent tape in a battery pack for removing internal pressure during thermal runaway according to the second embodiment of the present invention.

[0042] The second embodiment differs from the first embodiment in that a cut line 310 is formed in the vent tape 300 .

[0043] In this embodiment, the cut line 310 has a circular shape and is formed so as to surround the vent hole 110 from the outside of the vent hole 110 in the vent tape 300. The diameter of the cut line may be the same as or larger than the diameter of the vent hole 110.

[0044] Specifically, the cutout line 310 includes a plurality of cutout holes 311 spaced apart from one another as shown, and each cutout hole 311 has an arc shape that forms a portion of a circle. Therefore, each cutout hole 311 gathers together to form a single circular shape.

[0045] In the second embodiment of the present invention, the inside of the case 50 is normally sealed off from the outside to prevent foreign matter from entering. However, in the event of thermal runaway of the battery pack, when the internal pressure rises due to gas generated inside the battery pack 1000 and exceeds a certain pressure, a part or all of the cut line 310 portion of the vent tape 300 is cut off, the vent tape 300 is separated from the case 50 or the upper housing 100, and the internal gas is discharged through the vent hole 110 and the separated cut line portion, thereby removing the internal pressure.

[0046] In addition, in the second embodiment of the present invention, the exhaust pressure of the exhaust gas can be adjusted by adjusting the width of each cutout hole 311 constituting the cutout line 310, the interval between the cutout holes 311, and the like.

[0047] Specifically, the spacing between the cutout holes 311 can be increased to increase the base pressure at which the exhaust gas is discharged, and the spacing between the cutout holes 311 can be decreased to decrease the base pressure at which the exhaust gas is discharged.

[0048] Also, the width of the cutout hole 311 can be increased to decrease the base pressure at which the exhaust gas is discharged, and the width of the cutout hole 311 can be decreased to increase the base pressure at which the exhaust gas is discharged.

[0049] The other configurations and effects are similar to those of the first embodiment, and therefore a detailed description thereof will be omitted.

[0050] Next, a battery pack for removing internal pressure during thermal runaway according to a third embodiment of the present invention will be described. Figures 6 and 7 are enlarged views of a vent tape in a battery pack for removing internal pressure during thermal runaway according to the third embodiment of the present invention, Figure 8 is a view showing that internal gas is discharged through a vent hole in Figure 6, and Figure 9 is a view showing that internal gas is discharged through a vent hole in Figure 7.

[0051] The third embodiment differs from the second embodiment in that the cut line 310 of the vent tape 300 is in the shape of a circular arc.

[0052] In the third embodiment, unlike the second embodiment, the cutoff line 310 is not circular but arc-shaped, and FIGS. 6 and 7 show an example in which the cutoff line 310 is semicircular.

[0053] FIG. 6 is a diagram showing an example in which the cut line 310 is disposed on the lower side of the vent hole 110, and FIG. 7 is a diagram showing an example in which the cut line 310 is disposed on the upper side of the vent hole 110. As shown in FIG.

[0054] In the third embodiment, when the internal pressure rises due to gas generated inside battery pack 1000 during thermal runaway of the battery pack and exceeds a certain pressure, the cut line 310 portion in vent tape 300 is cut off, and when cut line 310 is positioned on the lower side of vent hole 110 as shown in FIG. 6, gas that has passed through vent hole 110 is discharged downward (see FIG. 8), and when cut line 310 is positioned on the upper side of the vent hole as shown in FIG. 7, gas that has passed through vent hole 110 is discharged upward (see FIG. 9).

[0055] Therefore, in the third embodiment of the present invention, the cut line 310 has an arc shape, and there is an advantage in that the exhaust direction of the exhaust gas can be adjusted by changing the formation position of the cut line 310. Therefore, the cut line 310 may be disposed on the left or right side of the vent hole 110, and in the case where there are two vent holes 110 as shown in the figure, the cut line 310 disposed in the left vent hole 110 may be disposed on the left (or right) side of the vent hole 110, and the cut line 310 disposed in the right vent hole 110 may be disposed on the right (or left) side of the vent hole 110.

[0056] Although the cut lines are semicircular in FIGS. 6 and 7, they may be arcs smaller or larger than a semicircle.

[0057] Next, a battery pack for removing internal pressure during thermal runaway according to a fourth embodiment of the present invention will be described. Figures 10 and 11 are diagrams showing the battery pack according to the fourth embodiment of the present invention.

[0058] The fourth embodiment differs from the above-described embodiments in that a gas exhaust tube 150 is provided in communication with the vent hole 110, and a vent tape 300 is arranged to cover the end of the gas exhaust tube 150.

[0059] Specifically, the gas exhaust tube 150 is connected to the vent hole 110 from the case 50 or the upper housing 100 and extends to the outside by a certain length. One end of the gas exhaust tube 150 is connected to the vent hole 110 and the other end of the gas exhaust tube 150 is arranged to protrude to the outside by a certain length and has an extension portion 170 at the other end.

[0060] In this embodiment, the extension portion 170 is flat and is disposed at the other end of the gas exhaust tube 150 so as to have a shape that extends outward from the outer circumferential surface of the gas exhaust tube 150 .

[0061] A communication hole 171 that communicates with the gas exhaust tube 150 is formed in the center of the expansion portion 170. The diameter of the communication hole 171 may be the same as or larger than the inner diameter of the gas exhaust tube 150.

[0062] The vent tape 300 is attached to the expanded portion 170. The vent tape 300 is provided on the expanded portion 170 so as to cover the end of the gas exhaust tube 150 and the communication hole 171.

[0063] In the fourth embodiment, when the internal pressure rises due to gas generated inside the battery pack 1000 during thermal runaway of the battery pack, the gas is guided to the gas exhaust tube 150 through the vent hole 110, and is discharged to the outside when the other end of the gas exhaust tube 150 is separated from the vent tape 300 provided on the expansion section 170, thereby removing the internal pressure.

[0064] In this embodiment, the gas exhaust tube 150 may be connected to the case 50 or the upper housing 100 so as to extend in an upward, downward, left or right direction, and the gas exhaust tube 150 may extend straight or have a bent portion that is bent to one side, or may be formed to be bent to one side.

[0065] As described above, in the fourth embodiment, the internal gas is guided and discharged by the gas exhaust tube 150 connected to the vent hole 110, and the gas exhaust direction can be adjusted by adjusting the direction in which the gas exhaust tube 150 extends from the case 50 or the upper housing 100.

[0066] In the fourth embodiment, the vent tape 300 may further include the cut line 310 in the second and third embodiments (see FIG. 11).

[0067] At this time, the cut line 310 may be disposed on the outside of the inner circumferential surface of the gas exhaust tube 150 in the expansion portion 170, or the cut line 310 may be disposed so as to surround the inner periphery (the cross-sectional hole or the communication hole 171 of the moving passage) of the gas exhaust tube 150 in the expansion portion 170. Moreover, the cut line 310 may be circular or arc-shaped, similar to the second and third embodiments.

[0068] The other configurations and effects are similar to those of the above-described embodiment, and therefore detailed description thereof will be omitted.

[0069] The present invention has been described above with reference to preferred embodiments thereof. However, the present invention is not limited to the above-described embodiments. A person having ordinary knowledge in the technical field to which the present invention pertains can modify and implement the present invention in various ways without departing from the spirit of the present invention. [Industrial Applicability]

[0070] According to the present invention, it is possible to provide a battery pack capable of quickly removing internal pressure in the event of thermal runaway. [Explanation of symbols]

[0071] 1 Upper housing 2 Lower housing 10 Battery Pack 50 cases 100 Upper housing 110 Vent Hole 150 Gas exhaust tube 170 Extension 171 Communication hole 200 Lower Housing 300 Vent Tape 310 Cutting line 311 Cutout hole 400 Gasket 500 Battery Module 1000 Battery Pack

Claims

1. one or more battery modules; and A case for housing the battery module; The case is A vent hole for discharging gas from the interior; and a vent tape attached to the case so as to cover the vent hole; The battery pack includes a relieving means for relieving internal pressure during thermal runaway.

2. The case is A lower housing; and an upper housing coupled to an upper side of the lower housing; The battery pack for removing internal pressure during thermal runaway according to claim 1 , further comprising:

3. The battery pack for relieving internal pressure during thermal runaway according to claim 2 , wherein the vent hole is disposed in the upper housing.

4. The battery pack for relieving internal pressure during thermal runaway according to claim 3 , wherein a plurality of the vent holes are provided.

5. The battery pack for relieving internal pressure during thermal runaway according to claim 1 , wherein the vent tape includes a cut line.

6. The battery pack for relieving internal pressure during thermal runaway according to claim 5 , wherein the cut line is disposed outside the vent hole.

7. The battery pack for relieving internal pressure during thermal runaway according to claim 6 , wherein the cut line is formed to surround the vent hole.

8. 6. The battery pack for removing internal pressure during thermal runaway according to claim 5, wherein the cut line is circular.

9. 6. The battery pack for removing internal pressure during thermal runaway according to claim 5, wherein the cut line is in the shape of a circular arc.

10. one or more battery modules; and A case for housing the battery module; The case is Vent holes to allow gases to escape from the interior; a gas exhaust tube communicating with the vent hole and extending from the case to the outside; and a vent tape covering the end of the gas exhaust tube; The battery pack includes a relieving means for relieving internal pressure during thermal runaway.

11. 11. The battery pack for relieving internal pressure during thermal runaway according to claim 10, further comprising an extension portion disposed at an end of the gas exhaust tube and extending outward from the end of the gas exhaust tube.

12. The battery pack for relieving internal pressure during thermal runaway according to claim 11 , wherein the vent tape is attached to the extension portion.

13. The battery pack for relieving internal pressure during thermal runaway according to claim 12 , wherein the vent tape includes a cut line.

14. The battery pack for removing internal pressure during thermal runaway according to claim 13 , wherein the cut line is disposed outside an inner circumferential surface of the gas exhaust tube in the expansion portion.

15. The battery pack for removing internal pressure during thermal runaway according to claim 13 , wherein the cut line is formed to surround an inner circumference of the gas exhaust tube.

16. The battery pack for removing internal pressure during thermal runaway according to claim 13 , wherein the cut line has a circular shape.

17. The battery pack for removing internal pressure during thermal runaway according to claim 13 , wherein the cut line is in the shape of a circular arc.

Images